1. Field of the Invention
The present invention relates generally to electronic devices such as USB-type connecting devices for connecting various USB-type interface equipments, and, more particularly, to a structure of a contact point unit exposed through the surface of the casing of a USB-type connecting device.
2. Description of the Related Art
In recent years, Universal Serial Bus (USB)-type interfaces (hereinafter referred to as xe2x80x9cUSB interfacesxe2x80x9d) have been employed as common interfaces for connecting various peripheral equipments, such as keyboard, mouse, and printer, to a personal computer, for instance.
In order to connect a plurality of USB interface peripheral equipments to a personal computer, a USB hub provided with a plurality of USB interface connectors is used.
In a USB interface, a cable made up of two signal lines and two power lines is used, so that power can be supplied to the peripheral equipments from each USB port via the USB hub.
FIG. 1 is a schematic view of the structure of a USB hub 1.
The USB hub 1 comprises a casing 2, a first USB port 3 formed by a USB connector disposed on the casing 2, second USB ports 4 formed by a plurality (four in FIG. 1) of USB connectors disposed on the casing 2, and a USB hub circuit 5 installed in the casing 2. The first USB port 3 is connected to the host of the USB hub circuit 5, and of the second USB ports 4 is connected to the lower layer side of the USB hub circuit 5.
As shown in FIG. 2, a personal computer is connected to the first USB port 3, while a keyboard 6, a mouse 7, a printer 8, and a scanner 9, each of which is suitable for USB connection, are connected to the second USB ports 4.
With this structure, the keyboard 6, the mouse 7, the printer 8, and the scanner 9 can be used through the personal computer via the USB hub 1.
Furthermore, the USB hub 1 has a layer structure. For instance, a 6-layer USB hub enables the use of 127 peripheral equipments. Also, such a layer-structured USB hub can be connected by hot-line connection (i.e., hot plugs). Thus, the usefulness of a personal computer can be increased further.
However, the USB hub 1 has disadvantages in that peripheral equipments are connected to the USB hub 1 via cables, and that the USB hub 1 is connected to a personal computer via a cable. Accordingly, a plurality of cables are required for the USB hub 1, and a large enough space for accommodating the cables is needed. Also, the arrangement of the cables becomes complicated.
To eliminate the above disadvantages, the USB hub 1 can be provided with a terminal unit exposed through the surface of the casing 2, so that the USB hub 1 can be connected to peripheral equipments without cables. However, if a person inadvertently touches such an exposed terminal unit with a finger, the terminal unit easily corrodes due to the fat of the finger, or the finger generates static electricity, resulting in a breakdown of the peripheral equipments.
Accordingly, it is an object of the present invention to provide an electronic device comprising:
a casing having a substrate disposed therein and a window formed on a surface thereof;
a terminal unit that is formed on the substrate, and comprises one or more terminals exposed through the window; and
a cover that is detachably mounted to the window, and covers and protects the window.
With the above electronic device, no one can inadvertently touch the terminals of the terminal unit. Thus, the terminals can be prevented from corroding due to the fat of a finger, and peripheral equipments connected to the electronic device can be prevented from breaking down due to static electric generated by a finger.
In the electronic device of the present invention, the cover is provided with ribs formed by slits on both sides, and the window is provided with tongues protruding inwardly from both sides. When the cover is attached to the window, the ribs are engaged with the tongues so that the cover is secured to the window.
With this structure, the cover is guided along the window to a predetermined closing position. Thus, the cover can be easily mounted to the window.
In the electronic device of the present invention, each of the ribs is slightly shorter than each corresponding side of the window, and each of the tongues is provided with a stopper protrusion on the top end. When the cover is attached to the window, the stopper protrusions are engaged with gaps between the peripheries of the respective ribs and the periphery of the window, so that the cover is secured to the window.
With this structure, the stopper protrusions are engaged with the gaps between the peripheries of the ribs and the periphery of the window. Thus, the cover can be secured in the predetermined closing position.
In the electronic device of the present invention, a frame for separating the terminals from each other is disposed between the terminals. The frame is collectively formed with the casing.
With this structure, the terminals are protected by the frame even when the cover is not attached to the window. Thus, the terminals can be protected from an inadvertent touch.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.